Fuse-box.



IP. J. MGDONALD.

y FUSE B0X. Y

APPLICATION FILED MAR. 18, 1908.

995,702. K Patented June2o,1911.

Fati

PATRICK J'. MCDONALD, 0F ROCHESTER, NEW YORK, ASSIGNOR 0F OIQ'E-ILALI`T0 GEORGE H. SMITH, F ROCHESTER, NEW YORK.

FUSE-BOX.

Specification of Letters Patent.

Application filed March 18, 1908.

Patented June 20, 1911.

serial No. 421,934.

To'aZZ whom it may concern:

Be it known that I, PATRICK J. Mo- DoNALn, of Rochester, in the countyof -Monroe and State of New York, have invented certain new and usefulImprovements in Fuse-Boxes; and do hereby declare the following to be afull, clear, and exact description of the same, reference being hadl tothe'accompanying drawings, forming a part of the specification, and tothe reference-numerals marked thereon.

This invention relates to Jfuse boxes, and

more particularly to devices of this kind j adapted to be used aslightning arresters in high tension current circuits.

An object of the invention is to provide a fuse box in which theterminals are so arranged and separated that the jumping of a spark fromone terminal to another is practically impossible. y

Another object is to' provide for fuse boxes and the other electricaldevices, cooperating terminals in which rm contact is secured, and whichare interlocked to pre vent them from becoming accidentally separated.

Still anot-her object is to construct a fuse box in which a groundconductor is so arranged and constructed that upon the burning of afuse, the excess of current will be conducted to the ground, and theground circuit will then automatically open to prevent particles of thefuse establishing a circuit between the terminals and the groundconductor.

To these and other ends the invention consists in certain improvementsand combina.- tions of parts all as will be hereinafter .more fullydescribed, the novel features being pointed out in the claims at the endof the specification. y

ln the drawings: Figure l is a longitudinal section of a fuse boxembodying my improvements. Fig. 2 is a transverse section on the linea-a of Fig. 1. Fig. 3 is a top plan view of the box with the coverremoved.

Fig. 4 is a longitudinal section on line Zz-v-V l of Fig. 3. Fig. 5'is atransverse section on tive View of one of the compressible terminals,and Fig. 7 is a view of the key for removing'r the compressibleterminals.l

With more extended reference to -the drawings. A indicates an insulatingsupport or base which in this instance is provided with two pairs ofterminals B, to be more particularly described. To prevent a sparkjumping from one terminal of one pair to a terminal of the other pair,there is arranged between the two pairs of terminals, an insulatingbarrier l which is integral with the base A. and extends transversely ofsaid base between the pairs of terminals.

Insulated fuses C, as for instance, fuse wires 2 and insulations 2a,pass about the barrier and each carries at its ends, terminals D tocoperate with the terminals B on the support. -These terminals B and Dmay be of any suitable construction, but the novel forms, herein shown,have special advantages in fuse boxes, as they are so arranged that theyprevent spark jumping.

As shown, the terminals Bare hollow and A are rectangular in crosssection, being arranged in pockets 3 in the base or support and spacedfromthe upper and the lower ends of the said pockets. Each of thepockets 3 is provided with a lateral outlet 4 and has one of its wallsformed With'a vertical groove 5 branching from the outlet, the line wire6 having its insulation inserted in the outlet t and its conductor wirebent laterally into the groove 5 to bear against a wall of the terminalB. Below the lower end of each terminal B, the pockets are enlarg-ed onopposite sides, asat 7 to receive locking projections on the coperatingterminal D, as will be described.

Each of the terminals D, herein shown, is compressible and comprises awire attaching portion 8 or head, adapted to rest upon the base orsupport/A about a pocket 3, the wire 2 being, in the present instance,soldered thereto. A pair of yielding members, preferably in the form oftwo spring arms, is carried by the wire attaching portion' and Jforinterlocking the terminal D with a terminal B, this means, in thisinstance, comprising a laterally extending projection 10 ,sradapted toengage beneath the lower end of the line c-c of Fig. 4. Fig. 6 is aperspeccontact B and to extend into an enlarged portion 7 of a pocket 3.To remove a. terminal vD, a key, in the form of a U-shaped member 11,has its arms adapted to be inserted into a poeket on opposite sides ofYYthe spring arms ot the te'minai/Ijise that the ends of the key willride on the curved contacting portions 9 and compress rthe said terminalto move the interlocking projections 10 from engagement with the lowerend of the terminal l The barrier 1 is formed with grooves 12corresponding in number to the fuses C, to hold the latter againstlateral displacement; ,and these grooves have lateral outlets '13 topermit the escape of fused portions, thus preventin f the groovesholding the fuses together an thereby maintaining connections betweenthe 'terminals after a fuse has been blown.

To conduct 'the encess of current away from a blowing fuse, l provide aground conductor, which rests against fuse C, between the terminals ofthe latter, the Yfuse having its insulation weakened, as for instance,recessed at 1li, and the Iground conductor being arranged to projectintothis recess. rlhis ground conductor comprises circuit breaking oropening device, which is held in circuit closing position by one ot thefuses C, and which automatically moves to break the ground circuit fromthe inse, when the fuso has been destroyed, thus preventing particles ofthe fuse maintaining a circuit from a terminal to and through the groundconductor.

In the present instance, the ground conductor passes through a groove 16in the under. side of the base or support, to a transverse pocket 17 inwhich is arranged a binding screw 18 extending through a vertical bore19, to a vertical pocket 20, having an anchoring nut 21 arrangedtherein. The binding screw 18 also retains within the pocket 17, a leafspring 22 which projects from both sides of the binding 'screw andbranches the ground conductor. Each branch ot' the `ground conductorembodies an automatic circuit breaking device, which, in this instance,is in the form ot a plunger 25%, arranged in a vertical bore in thesupport, and held against one free end ot' thc leaf spring 22 by one ot'the Yfuses C, positioned within a groove 12; thc lealc spring yieldingslightly, as shown in Fig. 2, so that a firm contact is formed betweenit and the plunger 22. The plunger is, through a coil spring 24, movedautomatically when its retaining tuse C burns, the bore in which theplunger moves being enlarged at its upper portion. as at 25, to providea seat for the spring, and the plunger boing formed at its upper endwith a head 2G lo provide au abutment for the spring.

The fuse parts are housed ,by a cover 27, preferably shaped to conformto the upper surface ot the support, .and having` an insulatinnr lining28. Thedovice is mounted in any suitable manner. as for instance. bybolts 20 passing through openings 30 in the support A.

aow/os l claim as my invention@ 1. ln a fuse box, a support, open endedhollow terminals on the support, and a rcmovable fuse carrying terminalsat opposite ends, each vformed to pass through one oiE the hollowterminals and having locking devices to engage below the lower end ofthe latter.

2. ln a fuse box, a support, hollow terminals carried by the support,and a fuse carrying at each end a terminal formed of spring arms adaptedto engage the inner walls of a hollow terminal and provided with meansto interlock with said terminal.

3. ln a fuse box, a support, hollow terminals carriedby the support, anda fuse "carrying at each aend a terminal formed ot spring arms adaptedto engage the inner walls oi a hollow `erminal and provided with lateralprojections to interlock with said latter terminal.

4. Yin a fuse box, a support, open ended hollow terminals carried by thesupport, and a fuse carrying at each end. a terminal comprising springlarms alapted to engage the inner walls ot a hollow terminal and formedwith outwardly curved contacting portions and with lateral projectionsat its ends, the curved, portions engaging opposite inner walls of ahollow terminal, and the lateral projections engaging an cud of the saidhollow terminal. I

5. A. fuse provided at its ends with terminals each comprising afuse-wire attaching portion, and spring arms'projccting from theattaching portion, each spring arm being formed with an outwardly curvedcontacting portion between its ends, and with an outwardly turnedlateral projection at its free end.

6. An electric terminal, comprising a wire lattaching portion, audspring ,arms extending from said portionand provided with outwardlycurved contacting portions between their ends and with outwardly turnedlateral extensions at their free ends.

7. The combination with an insulating support, of a hollow terminalarranged on the support, and a compressible terminal adapted forcpcration with the hollow terminal, and provided with means moved out ofinterlocking connection with the hollow terminal upon the compression ofthc said cooperating terminal,

8. In a fuse box, a support, an insulated fuse having a portion of itsinsulation weakcned, and a ground conductor hcld vicldably in engagementwith the weakened portion.

9. ln a fuse box. a support, au insulated fuse having a portion ot itsinsulation provided with a notch. and a `ground conductor hold yieldablyin Contact with the notch.

10. ln a -fusebox, a fuse. and a ground connection comprising means heldin circuit closing position by the fuse and moved auto matioally tobreak the Circuit when the fuse blows out.

vll. ln a fuso box, a' fuse, and a ground connection Comprising aplunger held in cifcuit closing position by the fuse, and means movingthe plunger automatically to break ibo circuit when the fuse blows out.

l2. In a fuse box, a fuse, and a ground connection comprising a membez'held in circuit closing position by the fuse, and a spring vmowing themember to break the ground oix'cuit when the fuse blows out.'

13. LVD, a fuse box, an insulating ,appo/t, a fuso arranged on one sideof the rsupport 15 and a ground Conduoor comprising. a flat spring, aplunger adaped to engage the free end of the spring and to be heldthereagainst by the fuse, and a spring for moving tho/ plunger out ofContact with the flat spring 20 when 'the' fuso blows out,

mamon' J. MCDONALD.

'Vitnssses: v

RUSSELL B. GMFFTH, lf-. Simms.

